1. Field of the Invention
The present invention relates to a speech recognition apparatus for recognizing input speech data and performing an operation according to the recognition result.
2. Description of the Related Art
When a conventional speech recognition apparatus incorporated in an electronic instrument or the like receives a speech input, the apparatus recognizes speech data of the input speech over a predetermined time and starts a predetermined operation in accordance with the recognition result after recognition is finished.
Speech recognition techniques of this type are described in, for example, U.S. Pat Nos. 4,158,750, 4,461,023, 4,532,648 and 4,596,031.
When the above conventional speech recognition apparatus is incorporated in, e.g., a stopwatch device or timer device to control start or stop of a time measurement operation in accordance with a speech such as "start" or "stop", the following problem arises. That is, in a track or swimming race, for example, assume that racers or swimmers start in accordance with a speech "start" and a stopwatch device recognizes the speech "start" and then starts time measurement. In this case, the competitors start not after the speech "start" is completely finished but simultaneously with start of the speech "start". The stopwatch device, however, starts the time measurement after the speech "start" is completely input and recognized. Therefore, since a time difference is produced between the start of the competitors and that of time measurement of the stopwatch device, a correct measurement time cannot be obtained. This problem is similarly posed, as in the case of "start", when measurement is to be stopped by a speech "stop" or elapsed time data is to be obtained by a speech such as "lap" or "split".
When the speech recognition apparatus is incorporated in a video tape recorder or speech recording device to start or stop video or sound recording by a speech sound, the same problem as in the case of the stopwatch device arises. In addition, for example, in a system in which different data are automatically and selectively displayed on a screen at a predetermined time interval and desired data can be held on the screen by a speech sound of "stop" when it is displayed on the screen, the same problem is posed.